The easiest way to smooth out your pedal stroke is to take a piece of crap old Cannondale and set it up to run single-speed.  When you do it though, make sure it has a very jacked up chain-line and use a chain tensioner.  Then do some hill repeats until the chain tensioner explodes and you’re left with a slack chain halfway through the ride.  Then you have no choice but to either pedal as smooth as a baby’s butt or stop and put your chain back on every 50 feet.

…not that I would know that from this morning’s ride, I’m just guessing that’s how you do it…